There is disclosed in U.S. Pat. No. 4,493,525, a first electrical connector having a circular cross-section first mating portion and a second electrical connector having a circular cross-section, shielded, second mating portion for receiving and mating with the first mating portion in a mating direction, the second mating portion having thereon a flexible latch arm provided with a protuberance proximate to its end, the first electrical connector having a latching shoulder provided in the insulating housing thereof, against which the protrusion can latch so as to retain the first and second mating portions in mating relationship. According to U.S. Pat. No. 4,493,525, the first mating portion is surrounded by a ring of spring fingers, projecting from a front shield of the first connector for resiliently engaging the shielding of said second mating portion when it is mated with the first mating portion. U.S. Pat. No. 4,548,455 discloses means for supporting such a latch arm when the connectors have been mated, so that the protuberance is secured in its latching position against a latching shoulder, said means being actable to release the arm, so that the protuberance can be depressed by the latching shoulder in order to allow the connectors to be unmated.